"Maybe someone can point out how slabbing has ruined, coins, stamps, collectors cards and every hobby it has invaded?"
I gave the full history on the stamp hobby several weeks ago. As a collector I watched it unfold.
Although Ive never been involved, I gather it was pretty much the same with collectors cards.
It is 100% about creating an artificially over-inflated investment environment. It lasts a few years and then the $hit hits the fan.